Technical Field
The present invention relates generally to electronic devices and, in particular, to incorporating arrays of Josephson junctions in the Josephson ring modulators which constitute the nonlinear dispersive medium in Josephson parametric converters.
Description of the Related Art
A Josephson ring modulator (JRM) is nonlinear dispersive element based on Josephson tunnel junctions that can perform three-wave mixing of microwave signals at the quantum limit. The JRM consists of Josephson Junctions (JJs). In order to construct a non-degenerate parametric'device that is the Josephson parametric converter (JPC), which is capable of amplifying and/or mixing microwave signals at the quantum limit, the JRM is incorporated into two microwave resonators at an RF-current anti-node of their fundamental Eignmodes. As has been demonstrated in several experimental and theoretical works, the performances of these JPCs, namely power gain, dynamical bandwidth, and dynamic range, are strongly dependent on the critical current of the JJs of the JRM, the specific realization of the electromagnetic environment (i.e., the microwave resonators), and the coupling between the JRM and the resonators.